Q: What specific battery maintenance is necessary to stave off low voltage concerns?
A: For battery maintenance, diligent and frequent monitoring of battery voltage when the engine is switched off for more than several hours is very important. Also, be sure to maintain clean battery terminals that are torqued solidly. These clean, tight connections are mandatory. To ensure that all batteries are always up to the task, cold cranking amp (CCA) or load testing of each battery individually is also essential.— Mark Burnside, Maxwell Technologies, senior product manager—engine starting products.
Q: What should we keep in mind for trucks with a heavier parasitic load?
A: Remember, the deeper the discharge cycle of the batteries, the shorter the life. If one cannot turn off these parasitic loads, look for other ways to manage these loads such as solar or on-board AC chargers, to mention a few. These type of devices could keep the battery pack from being severely discharged. —Bruce Purkey, chief creative engineer, Purkey’s Fleet Electric.
Q: What type of low voltage disconnects are commonly used?
A: The most common disconnect we see are the manual battery shut downs. These completely disconnect the batteries from the truck, thus prolonging battery life. With some electric auxiliary power units (APU) there is an automated system that shuts down when low battery voltage is reached to protect the cranking cycle. There can also be a split battery system where hotel loads are running from a number of batteries that are separated from the cranking batteries. — Danny Ritter, national technical support manager, heavy-duty group, Mitsubishi Electrical Automotive America.
Q: How does low voltage impact the alternator?
A: When voltage is low in the battery due to a low state of charge, amps during starting and charging must be higher than normal. This forces the alternator to work harder at high amperage as it tries to recharge the batteries. This higher heat in the alternator will shorten its life. Be sure that the truck can be used in its hotel/sleeper function without discharging the battery below 11.9 volts under load. When the voltage falls below that threshold, the batteries will not have sufficient stored energy to start the engine. —Bruce Essig, Odyssey national program manager for EnerSys.
For more electrical load insight and advice, be sure to read FE’s full feature here.
